Cage, John (1912–1992)

American avant-garde composer perhaps best known for the quietest piece
of music ever written. His piano composition 4'33' calls for the player
to sit in silence for 273 seconds – this being the number of degrees
below zero on the centigrade scale of absolute
zero at which molecular motion stops. 4'33" was inspired by Cage's visit
to Harvard University's anechoic chamber about which he wrote:

There is no such thing as empty space or empty
time. There is always something to hear or something to see. In fact,
try as we might to make a silence, we cannot. For certain engineering
purposes, it is desirable to have as silent a situation as possible. Such
a room is called an anechoic chamber, its walls made of special materials,
a room without echoes. I entered one at Harvard University ... and heard
two sounds, one a high and one a low. When I described them to the engineer
in charge, he informed me that the high one was my nervous system and
the low one was my blood circulation.

Cage's 4'33" breaks traditional boundaries by shifting attention from the
stage to the audience and even beyond the concert hall. The listener becomes
aware of all sorts of sound, from the mundane to the profound, from the
expected to the surprising, from the intimate to the cosmic – shifting
in seats, riffling programs, breathing, a creaking door, passing traffic,
a recaptured memory. Is sitting quietly alone for 273 seconds equivalent
to a private performance (and audience) of the piece? Or, in the final analysis,
is it all pretentious nonsense? In his essay on "Nothing" Martin Gardner wrote: "I have not heard 4'33" performed, but friends who have tell me it
is Cage's finest composition."

Cage challenged the listener to focus on the placement of sounds in his music for prepared piano and music using electronic equipment. Rocks (1986) requires radios, television sets, cassette machines, and machines emitting fixed sounds like vacuum players, buzzers, and alarms. In Child of Tree (1975) and Branches (1976) cactus spikes are played with toothpicks.